What did you do to your NNBS GMT900 Tahoe/Yukon Today?

spiritman said:

You know I didn’t realize how bright they would be until last night.


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iamdub said:

If you mean the flip-top caps that the bolt goes through the bottom half then the cap snaps over it, I decided against this style because I'd expect the plastic to warp, shrink, dry rot, etc. in the sunlight and heat and, eventually, the caps wouldn't stay snapped closed.

If you were talking about the caps that are basically a disc with a hex-shaped recess to fit over the bolt head, that would work as well but would need to be adhered somehow. They would also sit much higher off the roof than caps snapped into set screws that were flush with the roof line. Thread sealer, such as what is used on bolts that protrude into water jackets in engine blocks should be plenty sufficient as it is (obviously) heat- and water resistant. The flat caps I'd snap over the set screws would have a layer of adhesive sealant (windshield adhesive, etc.) applied to the underside to secure them as well as seal them from the outside. Windshield adhesive is designed to adhere and seal and not weather, so it's ideal. When I press the cap onto the set screw, the adhesive will squish out around the edges. I'd just wipe off the escess while it's still wet. The threaded insert will be completely encapsulated by plastic that's covered by body paint and UV-reflective clear coat as well as adhesive sealant designed for such a purpose. The flat caps would be maybe 2mm high rather than the hex bolt caps which would stand off the body the thickness of the bolt head plus the thickness of the plastic itself. The lower profile would be much cleaner.




The problem is more common with electronics that are sealed in boxes with regular silicone. The solder and copper are more prone to react with the fumes released by the silicone as it cures. Used in an open automotive environment, the gases can escape. Maybe the problem is inconsistencies when applying the silicone that create air pockets under the cured silicone "skin" leading to corrosion? Maybe you don't apply the silicone excessively thick and you lay a consistent enough bead that there aren't any voids created to encapsulate gases. All I know is I've seen window frames rotted out all around because a leaking window gasket was sealed with household silicone sealant. Though, there are other factors involved such as the alloys in the metal the car body was stamped from and the chemicals used in the production of the silicone itself, all of which may (and likely) have changed over time. I'd still rather play it safe and use purpose-made stuff. Common household silicone sealant isn't as stable in constant outdoor environments as automotive windshield adhesive.

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spiritman said:

I installed 6 LED 578 bulbs in my 2011 Yukon Denali. They replaced the map and dome lights.


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07Burb said:

just made an appointment to get my new TPMS sensors installed on Friday morning. That light on the dash is driving me bonkers and it's time to make it go away. It better stay away for a while!! LOL

[rant]
The TPMS bullcrap is one my bigger annoyances with the newer cars/trucks. I wish there was a way to tune the system out. I hate it and it's useless to me.
[/rant]

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07Burb said:

just made an appointment to get my new TPMS sensors installed on Friday morning. That light on the dash is driving me bonkers and it's time to make it go away. It better stay away for a while!! LOL

[rant]
The TPMS bullcrap is one my bigger annoyances with the newer cars/trucks. I wish there was a way to tune the system out. I hate it and it's useless to me.
[/rant]

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89Suburban said:

I thought you needed to spend that money on an AC compressor for the Dually?? Phuck TPMS things...

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wjburken said:

I’ve seen people use tree rivets with a little silicone or RTV to plug holes as well. They are low profile.

https://www.mcmaster.com/tree-rivets

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the_tool_man said:

I'm not picking on you iamdub - this was just the post I picked to reply to out of several...

Several have suggested a combination of thread locking compound and plastic washer/cap/whatever. If you find a combination that works, great. Please share your success story after a few months in the weather. BUT...

Keep in mind that many plastics are severely embrittled by the chemical reaction that anaerobic thread locking compounds undergo as they cure. I've seen this multiple times, not the least of which at work, where we use Lexan (polycarbonate) panels to cover machinery openings. If an inexperienced assembler uses thread locking compound on any of the bolts, the panels crack within a couple of days, even with no stress applied.

I once repaired and re-calibrated a torque wrench where the handle retaining nut had come loose. I put Loctite on the nut "just to make sure". The next time I went to use the wrench, the handle (probably ABS or polystyrene) had cracked into dozens of pieces, just sitting in the toolbox drawer.

I can't say which plastics, under what environmental conditions, have an issue. And as iamdub pointed out, what happens in open air may be different than in an enclosed space with little or no ventilation. But I would recommend either using something else to seal the threads, or at least keep an eye on the plugs to make sure they don't crack.

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